2001 Prizm (same as Toyota Corolla from that year)
I was changing the sparkplugs the other day, and in pulling out one of the ignition coils (which was very solidly attached, for whatever reason) I cracked off a part of it. My question is how big of a deal that part is.
Essentially the spark plugs are screwed in at the bottom of a cylinder, and the ignition coil extends the length of that cylinder, attaching to the plugs at the bottom. At the top, the coils are screwed in to the engine. Just below the point where the coil gets screwed to the engine the coil has a round plastic “cap” and a gasket below it. The idea is that the hard plastic covers the cylinder. picture here
Part of the plastic cap is what broke off, so now the hole is covered at that point partially by just the gasket, which is not being tightly pressed against the engine cover.
My question is how big of a deal this is. My inclination is to think that it’s not a big deal at all, and the idea is just to make sure things don’t fall into the cylinder, and what with the gasket and the overall engine cover on these models it shouldn’t be a big concern. It’s not an expensive part to reorder, but I’m lazy about taking the stuff apart again if there’s no need.
But many times car companies make things for important reasons so it might be worth the effort. So if anyone has any expert opinions I’d be appreciative.
Engine vibration will work that ignition coil off. So, can you drive it, sure, but I’d drive to AutoZone or someplace to get a new coil. In theory you could order a new one but I don’t think the potential hassle of a loose ignition coil is worth that meager savings.
The coil is still solidly screwed to the engine, and that part is unaffected. The only part that is partially cracked off is the round “cap” part, below the part which attaches to the engine (or to the right of it in the linked picture, which is horizontal).
The rubber gasket is to keep dirt and mostly moisture out. A tiny bit of condensation could cause an arc at the top of the plug and misfire under the right conditions. If there is an open gap I would think about fixing it, otherwise drive it.
If it’s cold winter or dry warm where you’re located the humidity should be low and there should be no issue. If it’s humid or rainy keep it in mind…but it’s not a critical thing.
The screw on top of the coil is mostly just to stop it from wiggling around. The coil is primarily held in place with a metal clip at the end of the tube that resembles a good old fashioned spark plug wire boot.
I think as you’ve described it, you might have a problem with the tube part and the spark plug connection being able to move up and down too much and eventually wiggling loose. I think it should probably be okay, though, and worst case the coils are right on top of the engine so it’d take you about 10 seconds to snug the thing back on (with the engine off!) if it does start giving you grief.
You might have trouble with it letting more dust into the spark plug tube, so it might be a good idea to hit it with a shop vac before you change the spark plugs next, but that’s not a bad idea anyways. You might also potentially have problems with moisture building up in the tubes and shorting out the plug, leading to misfires, but that’d probably only be if you’re in a pretty damp climate.
No, the coil is held firmly in place by the bolt that fixes it to the valve cover. It’s not going to move at all.
It will probably be fine to run it as is unless and until it starts misfiring. If it does, and it’s verified that the broken coil is the cause, replace it then.
